Driver: enhance MSC version compatibility

[compnerd]

Summary

The version information for Visual Studio is spread over multiple variables.
The newer Windows SDK has started making use of some of the extended versioning
variables that were previously undefined. Enhance our compatibility definitions
for these cases.

_MSC_VER is defined to be the Major * 100 + Minor. _MSC_FULL_VER is defined to
be Major * 10000000 + Minor * 100000 + Build. And _MSC_BUILD is the build
revision of the compiler.

Extend the -fmsc-version option in a compatible manner. If the value is the
previous form of MMmm, then we assume that the build number is 0. Otherwise, a
specific build number may be passed by using the form MMmmbbbbb. Due to
bitwidth limitations of the option, it is currently not possible to define a
revision value.

[rnk]

lib/Basic/Targets.cpp

582

I'm not crazy about -fmsc-version=MMmmmbbbbb. How about -fmsc-version either takes a non-full number, or it takes a dot-separated number as described here? We can skip the patch version for now, since that's too many bits.

[compnerd]

lib/Basic/Targets.cpp

582

AFAICT, the value is a uint32_t. How would the dot separated value be passed to it? I would certainly prefer that.

[compnerd]

Incorporate Aaron's feedback.

[rnk]

lib/Basic/Targets.cpp

582

Change this line in CompilerInvocation.cpp to parse the dot separated value:

Opts.MSCVersion = getLastArgIntValue(Args, OPT_fmsc_version, 0, Diags);

[compnerd]

Address additional review comments.

[rnk]

lgtm with a simplification

lib/Frontend/CompilerInvocation.cpp

1197

I don't think this decltype stuff is necessary. LLVM assumes unsigned is 32-bit in lots of other places. I'd rather have this return 'unsigned', not take LangOpts, and have the caller assign the result to Opts.MSCVersion.

[compnerd]

Committed with indicated simplifications as SVN r211420.

lib/Basic/Targets.cpp

void getVisualStudioDefines(const LangOptions &Opts,
     if (Opts.CPlusPlus) {
       if (Opts.RTTI)
         Builder.defineMacro("_CPPRTTI");
 
       if (Opts.Exceptions)
         Builder.defineMacro("_CPPUNWIND");
     }
 
     if (!Opts.CharIsSigned)
       Builder.defineMacro("_CHAR_UNSIGNED");
 
     // FIXME: POSIXThreads isn't exactly the option this should be defined for,
     //        but it works for now.
     if (Opts.POSIXThreads)
       Builder.defineMacro("_MT");
 
-    if (Opts.MSCVersion != 0)
-      Builder.defineMacro("_MSC_VER", Twine(Opts.MSCVersion));
+    if (Opts.MSCVersion != 0) {
+      Builder.defineMacro("_MSC_VER", Twine(Opts.MSCVersion / 100000));
+      Builder.defineMacro("_MSC_FULL_VER", Twine(Opts.MSCVersion));
+      // FIXME We cannot encode the revision information into 32-bits
+      Builder.defineMacro("_MSC_BUILD", Twine(1));
+    }
 
     if (Opts.MicrosoftExt) {
       Builder.defineMacro("_MSC_EXTENSIONS");
 
       if (Opts.CPlusPlus11) {
         Builder.defineMacro("_RVALUE_REFERENCES_V2_SUPPORTED");
         Builder.defineMacro("_RVALUE_REFERENCES_SUPPORTED");
         Builder.defineMacro("_NATIVE_NULLPTR_SUPPORTED");

lib/Frontend/CompilerInvocation.cpp

 #include "clang/Driver/Util.h"
 #include "clang/Frontend/FrontendDiagnostic.h"
 #include "clang/Frontend/LangStandard.h"
 #include "clang/Frontend/Utils.h"
 #include "clang/Lex/HeaderSearchOptions.h"
 #include "clang/Serialization/ASTReader.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Option/OptTable.h"
 #include "llvm/Option/Option.h"
 #include "llvm/Support/CodeGen.h"
if (value == "default") {
     return ProtectedVisibility;
   }
 
   diags.Report(diag::err_drv_invalid_value)
     << arg->getAsString(args) << value;
   return DefaultVisibility;
 }
 
+static void parseMSCVersion(LangOptions &Opts, ArgList &Args,
+                            DiagnosticsEngine &Diags) {
+  decltype(Opts.MSCVersion) Version = 0;
+
+  if (auto Arg = Args.getLastArg(OPT_fmsc_version)) {
+    StringRef Value = Arg->getValue();
+
+    // The MSC versioning scheme involves four versioning components:
+    //  - Major
+    //  - Minor
+    //  - Build
+    //  - Patch
+    // We accept either the old style (_MSC_VER) value, or a _MSC_FULL_VER
+    // value.  Additionally, the value may be provided in the form of a more
+    // readable MM.mm.bbbbb.pp version.
+    //
+    // Unfortunately, due to the bit-width limitations, we cannot currently
+    // encode the value for the patch level.
+
+    if (Value.find('.') == StringRef::npos) {
+      if (Value.getAsInteger(10, Version))
+        Diags.Report(diag::err_drv_invalid_value)
+          << Arg->getAsString(Args) << Value;
+    } else {
+      bool Valid = true;
+      SmallVector<StringRef, 4> Components;
+      decltype(Opts.MSCVersion) VC[4] = {0};  // MM.mm.bbbbb.pp
+
+      Value.split(Components, ".", llvm::array_lengthof(VC));
+      for (unsigned CI = 0,
+                    CE = std::min(Components.size(), llvm::array_lengthof(VC));
+           CI < CE; ++CI) {
+        if (Components[CI].getAsInteger(10, VC[CI])) {
+          Diags.Report(diag::err_drv_invalid_value)
+            << Arg->getAsString(Args) << Value;
+          Valid = false;
+          break;
+        }
+      }
+
+      // FIXME we cannot encode the patch level
+      if (Valid)
+        Version = VC[0] * 10000000 + VC[1] * 100000 + VC[2];
+    }
+  }
+
+  Opts.MSCVersion = (Version < 100000) ? Version * 100000 : Version;
+}
+
 static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
                           DiagnosticsEngine &Diags) {
   // FIXME: Cleanup per-file based stuff.
   LangStandard::Kind LangStd = LangStandard::lang_unspecified;
   if (const Arg *A = Args.getLastArg(OPT_std_EQ)) {
     LangStd = llvm::StringSwitch<LangStandard::Kind>(A->getValue())
 #define LANGSTANDARD(id, name, desc, features) \
       .Case(name, LangStandard::lang_##id)
#include "clang/Frontend/LangStandards.def"
 
   Opts.DollarIdents = Args.hasFlag(OPT_fdollars_in_identifiers,
                                    OPT_fno_dollars_in_identifiers,
                                    Opts.DollarIdents);
   Opts.PascalStrings = Args.hasArg(OPT_fpascal_strings);
   Opts.MSVCCompat = Args.hasArg(OPT_fms_compatibility);
   Opts.MicrosoftExt = Opts.MSVCCompat || Args.hasArg(OPT_fms_extensions);
   Opts.AsmBlocks = Args.hasArg(OPT_fasm_blocks) || Opts.MicrosoftExt;
-  Opts.MSCVersion = getLastArgIntValue(Args, OPT_fmsc_version, 0, Diags);
+  parseMSCVersion(Opts, Args, Diags);
   Opts.VtorDispMode = getLastArgIntValue(Args, OPT_vtordisp_mode_EQ, 1, Diags);
   Opts.Borland = Args.hasArg(OPT_fborland_extensions);
   Opts.WritableStrings = Args.hasArg(OPT_fwritable_strings);
   Opts.ConstStrings = Args.hasFlag(OPT_fconst_strings, OPT_fno_const_strings,
                                    Opts.ConstStrings);
   if (Args.hasArg(OPT_fno_lax_vector_conversions))
     Opts.LaxVectorConversions = 0;
   if (Args.hasArg(OPT_fno_threadsafe_statics))

test/Driver/msc-version.c

+// RUN: %clang -target i686-windows -fms-compatibility -dM -E - </dev/null -o - | FileCheck %s -check-prefix CHECK-NO-MSC-VERSION
+
+// CHECK-NO-MSC-VERSION: _MSC_BUILD 1
+// CHECK-NO-MSC-VERSION: _MSC_FULL_VER 170000000
+// CHECK-NO-MSC-VERSION: _MSC_VER 1700
+
+// RUN: %clang -target i686-windows -fms-compatibility -fmsc-version=1600 -dM -E - </dev/null -o - | FileCheck %s -check-prefix CHECK-MSC-VERSION
+
+// CHECK-MSC-VERSION: _MSC_BUILD 1
+// CHECK-MSC-VERSION: _MSC_FULL_VER 160000000
+// CHECK-MSC-VERSION: _MSC_VER 1600
+
+// RUN: %clang -target i686-windows -fms-compatibility -fmsc-version=160030319 -dM -E - </dev/null -o - | FileCheck %s -check-prefix CHECK-MSC-VERSION-EXT
+
+// CHECK-MSC-VERSION-EXT: _MSC_BUILD 1
+// CHECK-MSC-VERSION-EXT: _MSC_FULL_VER 160030319
+// CHECK-MSC-VERSION-EXT: _MSC_VER 1600
+
+// RUN: %clang -target i686-windows -fms-compatibility -fmsc-version=17.00 -dM -E - </dev/null -o - | FileCheck %s -check-prefix CHECK-MSC-VERSION-MAJOR-MINOR
+
+// CHECK-MSC-VERSION-MAJOR-MINOR: _MSC_BUILD 1
+// CHECK-MSC-VERSION-MAJOR-MINOR: _MSC_FULL_VER 170000000
+// CHECK-MSC-VERSION-MAJOR-MINOR: _MSC_VER 1700
+
+// RUN: %clang -target i686-windows -fms-compatibility -fmsc-version=15.00.20706 -dM -E - </dev/null -o - | FileCheck %s -check-prefix CHECK-MSC-VERSION-MAJOR-MINOR-BUILD
+
+// CHECK-MSC-VERSION-MAJOR-MINOR-BUILD: _MSC_BUILD 1
+// CHECK-MSC-VERSION-MAJOR-MINOR-BUILD: _MSC_FULL_VER 150020706
+// CHECK-MSC-VERSION-MAJOR-MINOR-BUILD: _MSC_VER 1500
+
+// RUN: %clang -target i686-windows -fms-compatibility -fmsc-version=15.00.20706.01 -dM -E - </dev/null -o - | FileCheck %s -check-prefix CHECK-MSC-VERSION-MAJOR-MINOR-BUILD-PATCH
+
+// CHECK-MSC-VERSION-MAJOR-MINOR-BUILD-PATCH: _MSC_BUILD 1
+// CHECK-MSC-VERSION-MAJOR-MINOR-BUILD-PATCH: _MSC_FULL_VER 150020706
+// CHECK-MSC-VERSION-MAJOR-MINOR-BUILD-PATCH: _MSC_VER 1500
+